Orthopedic support unit fastener

ABSTRACT

A orthopedic support unit fastener composed of a female portion which is molded directly as part of an orthopedic support component such as a sternum brace and has reinforcing ridges extending between an outer ring and a central receptacle which receives a male portion.

This application is a division of U.S. application Ser. No. 08/438,748,filed May 10, 1995 now U.S. Pat. No. 5,632,722.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to orthopaedic cervical collars, particularlythose used in the treatment, stabilization and therapy of cervicaltrauma.

2. Description of Related Art

Various types of cervical collars have been developed in treatingconditions of the neck and cervical spine. Some of these collars areintended merely as support for whiplash and other such injuries wheresupport for the head and neck is needed. The primary objective for theuse of such a collar is to partially immobilize the head and neck, tomaintain a desired spinal alignment, to provide support for the head,and to relieve any spasm or strain to which the neck muscles may besubjected by transmitting weight or force from the head to the shouldersor adjacent area.

Other collars are intended to be used where near complete immobilizationof the head and neck are necessary such as in an EMS pre-hospitalsetting. There are a multitude of cervical collars intended to performone or more of the above-mentioned functions.

U.S. Pat. No. 3,572,328 to John L. Bond describes an adjustable,flexible cervical collar designed for universal use by providingvertically adjustable movable sections displaceable relative to oneanother and to a base portion.

U.S. Pat. No. 2,911,970 to W. L. Bartles pertains to a cervical collarhaving two piece construction which allows for adjustment of the forwardportion of the cervical collar. This allows for the use of a singlecollar by persons having different length necks as measured in the frontof the person.

Other collars intended for partial or total immobilization are shown inU.S. Pat. No. 4,413,619 and Reissue No. 32,219 to Garth. Such collarsare generally made by die-cutting plastic sheet material and attachingvarious pieces together to form a collar. Die cut collars have twospecific problems.

The first problem with die cut collars relates to the flexibility of thematerial from which the collar is formed. The material selected must beflexible enough to conform to the neck and head of the patient, whilebeing sufficiently rigid to maintain the head of the patient in a fixed,predetermined spatial relationship with the body of the patient.

The second problem with die cut collars, as with all die-cut materials,is that no matter how well the pieces may be designed, there is alwayswaste involved between pieces die-cut from a sheet. There is also wastefrom holes cut in those pieces. Accordingly, it would be more economicalif such a collar could be produced by injection molding.

Injection molding of cervical collars has been previously attempted.U.S. Pat. No. 5,038,759 to Morgenstern shows an injection moldedcervical orthopaedic device. While this solves the second problem byminimizing the waste generated by die cutting collars, it does notaddress the first problem of physical characteristics of the materialfrom which the collar is formed.

The material forming the collar must be sufficiently flexible to allowthe collar to conform to the neck of the patient on which it is placed.Yet the collar must have sufficient rigidity to hold the patient's neckin a predetermined position and sufficient toughness to withstandcontinued use. Of course, in the case of injection molding, the materialmust also be injection moldable. Most injection moldable materialsstrong and tough enough to maintain the head of a patient in apredetermined position are too stiff to be useful as a material for acervical collar. Even those materials which might be difficult to molddo not normally meet these conflicting criteria. Finally, the chosenmaterial should cause a minimum of interference with x-rays, magneticresonance imaging and other diagnostic procedures. Few or no materialscan meet all of these demands in a conventional molded or die cutcervical collar.

SUMMARY OF THE INVENTION

The present invention provides a cervical collar preferably formed froma thermoplastic material, which includes flexibility enhancing openingswhich allow the collar to conform properly to the shape of a patient'sneck. Most preferably, the collar is formed from linear low densitypolyethylene, which is an injection moldable material. The collar may beinjection molded and include female portions of medical rivets moldeddirectly into the collar.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front-view of the collar of the present invention secured toa patient.

FIG. 2 is a rear-view of the collar of the present invention secured toa patient.

FIG. 3 is a perspective view of the collar of the present inventionsecured to a patient.

FIG. 4 is a plan-view of the jaw support of the collar of the presentinvention.

FIG. 5 is a plan-view of the front side of the front semi-rigid portionof the collar of the present invention.

FIG. 6 is a plan-view of the occiput support of the collar of thepresent invention.

FIG. 7 is a plan-view of the rear semi-rigid portion of the collar ofthe present invention.

FIG. 8 is a plan-view of the rear side of the front semi-rigid portionof the collar of the present invention.

DETAILED DESCRIPTION OF THE FIGURES

As previously explained, the selection of material for use in producinga cervical collar is very important. The material must be sufficientlyrigid to hold the head of a patient in a predetermined position butsufficiently flexible to allow the collar to conform to the head of apatient. In a die cut collar, polyethylene and polypropylene are commonchoices as materials of construction, and any such commonly usedmaterial should perform well in the present invention.

The material selected for production of an injection molded collaraccording to the present invention is preferably a linear low-densitypolyethylene with a melt flow index of about 20. Material with a meltflow index of 50 was tested but the collar cracked after a few weeks ofuse. This demonstrates the need for careful selection of the material ofconstruction of the collar and the demands which are normally placed ona collar. In this case, while the material was sufficiently stiff tomaintain the head of the patient in a fixed, predetermined spatialrelationship to the body of the patient, the material was too brittle towithstand use for more than a short period of time.

The particular material preferred for use in injection molded collarsaccording to the present invention, is linear low-density polyethylene(LLDPE). In particular, Petrothene® GB564 linear low densitypolyethylene obtained from Quantum Chemical Corporation, Inc., VSIDivision of Cincinnati, Ohio was used to produce collars according tothe present invention.

LLDPE offers advantages over other resins which make it the desirablematerial for use in cervical collars generally and in injection moldedcervical collars in particular. LLDPE is more x-ray transparent thanhigh density polyethylene (HDPE). This is important since most cervicalcollar patients are trauma victims and x-rays must be taken for variousreasons, including insuring the proper alignment of the cervical spineafter application of a collar.

LLDPE is also less dense than HDPE, and more pliable. Thus, to obtainthe same stiffness of collar, the use of LLDPE requires more materialbut produces a thicker collar which is less likely to cut into the skinof a patient wearing the collar. Further, LLDPE is more temperaturetolerant than other materials and therefore performs better in non-idealconditions such as those found in emergency situations. LLDPE also hasno shape "memory, " and therefore, even if a collar of LLDPE is notstored flat, it can be flattened and shaped correctly prior to use. Itwill conform correctly to the neck of a patient without stress fromprior bending, regardless of prior storage conditions.

Referring now to FIGS. 1-3, cervical collar 10 comprises frontsemi-rigid portion 12 and rear semi-rigid portion 14. Front semi-rigidportion 12 comprises sternum brace 16 and jaw support 18. Sternum brace16 may also be seen in FIG. 5, and jaw support 18 may also be seen inFIG. 4. The pieces of cervical collar 10 may be injection molded or diecut. Injection molding the pieces of a collar allows inclusion ofstructures which would be impossible or very difficult in die-cutstructures.

As can be seen from FIG. 5, sternum brace 16 includes two hook-and-loopfastener positioning guides, right positioning guide 24 and leftpositioning guide 26. As used herein, the terms "right" and "left" aredefined as being from the point of view of a patient wearing the collar.Guides 24 and 26 each comprise a raised line around an area in which aloop portion of hook-and-loop fastener material 54 is to be applied.This aides in making certain the hook-and-loop fastener material iscorrectly placed on sternum brace 16. The inclusion of such a raisedline would be difficult or impossible in a die-cut collar, but such araised line is easily included in the injection molded collar of thepresent invention.

Sternum brace 16 also includes an opening 28 which allows access to thetrachea of the patient should an emergency tracheotomy or otherprocedure need to be performed on the neck of a patient after the collaris in place. Opening 28 is reinforced around its periphery with a raisedreinforcement rib 30. Opening 28 is also reinforced on the underside ofsternum brace 16 by reinforcement ribs 31, as may be seen from FIG. 8.Sternum brace 16 includes hook-and-loop fastener guide 32 which alsoincludes a raised reinforcement rib 30 around the periphery thereof.

The aforementioned features including guides 24 and 26 and raisedreinforcement ribs 30 are included in the injection molded collar of thepresent invention. In a die cut collar, guides 24 and 26, as well assuitable reinforcements could be included by bonding extra layers ofLLDPE onto sternum brace 16. Such a configuration is not shown in thefigures hereof. Rather only the injection molded embodiment is depicted.

Further, sternum brace 16 includes a mandibular relief area 70.Mandibular relief area 70 is located on the inside of sternum brace 16,as shown in FIG. 8. Area 70 can be a straight depressed channel runningacross sternum brace 16. In an injection molded collar, the mandibularrelief area 70 can be molded into sternum brace 16. In a die cut collar,area 70 could be formed by milling sternum brace 16. Of course, millingcould be used on a molded collar as well, but molding area 70 directlyinto the collar would be more efficient.

Area 70 allows sternum brace 16 to conform more closely to the jaw lineof a patient than would otherwise be possible. The area 70 is positionedsuch that it separates two upper portions 72 from the remaining (lower)portions of sternum brace 16. Area 70 acts as a hinge to allow upperportions 72 of sternum brace 70 to fold away from the patient to relievepressure created by the collar along the jaw line (mandible) of apatient. This helps reduce discomfort to the patient and reduces thechance of the patient developing decubitus ulcers along the jaw.

Alternatively, area 70 may encompass not only a channel, but also theupper portions 72. Area 70 would then be a general weakening of thecollar material throughout the area. Specifically, area 70 may beginwith the full thickness of the collar and become thinner through upperportion 72, to the edge of sternum brace 16. Thus, the entire area 70and 72 would be weakened and would allow flexibility.

Finally if the pieces of cervical collar 10 are injection molded,further advantages can be realized. For example, the injection moldingof sternum brace 16 allows female portions of plastic rivets 34 to beintegrally molded directly into sternum brace 16. Many modern cervicalcollars are secured together by means of plastic medical rivets (alsocalled snap fasteners because they make a "snap" sound when joined).These rivets have male portion 34a and female portion 34b. Once the twoportions are combined, it is difficult or impossible tonon-destructively open the rivet. Hence these rivets are useful forassembling a cervical collar where permanency of attachment is desired.Further, the plastic rivets are desirable as they do not interfere withx-rays, magnetic resonance imaging, or other diagnostic techniques.

Heretofore, such plastic medical rivets have been molded separately andpurchased by the manufacturer of the collar for use in assembling thecollar. The use of injection molding allows female portions 34b of theserivets to be molded into the collar which saves production costs. Due tothe shape of male portion 34a of rivet 34, specifically undercuts whichprovide locking strength to the rivet, molding the male portion of therivet into the collar is not practical. Therefore, it is still necessaryto produce male portion 34a of rivet 34 separately.

As can be seen from FIG. 5, female portions 34b of rivets 34 are moldeddirectly into sternum brace 16. Since sternum brace 16 is formed fromLLDPE, female portions 34b of rivets 34 are also formed from LLDPE.LLDPE is not as resistant to deformation as the material normally usedfor medical rivets. Therefore for rigidity and strength, female portion34b has been designed to include reinforcing ridges 36 around circularcentral receptacle 38. Central receptacle 38 is a continuous ring ofplastic with a hole in the middle. Central receptacle 38 receives maleportion 34a of rivet 34. Reinforcing ridges 36 are straight ridges whichextend from an outer ring 35 inwardly to receptacle 38 to reinforcecentral receptacle 38 and to add strength to female portion 34b of rivet34. Generally, reinforcing ridges 36 are equally spaced about thecircumference of central receptacle 38.

Jaw support 18 is attached to sternum brace 16 as shown in FIG. 4. Jawsupport 18 includes attachment holes 40 for attachment to sternum brace16. These are attached with rivets which fasten to sternum brace 16 atfemale rivet portions 42 which are identical to female rivet portions34b previously described. The right-most attachment hole 40 (as viewedfrom the patient) aligns with attachment hole 44 on sternum brace 16.Attachment hole 44 receives a removable attachment stud which allowsremoveable attachment of the right-most portion of chin-support 18 tosternum brace 16. This removeable attachment is desired since thecollars are generally shipped flat, and this removeable attachmentallows the collar to be reflattened after use. Jaw support 18 alsoincludes vent holes 46 which not only allow air and moisture to passthrough jaw support 18 but also affect flexibility of the jaw support toallow it to contour to the shape of the chin of the user.

Rivets 34 are also used to attach sternum brace padding 48 to sternumbrace 16. Jaw support padding 50 (as well as all other padding) may alsobe attached using rivets, or may be removably attached usinghook-and-loop fasteners, snaps, buttons, or other removeable means ofattachment. In this way, the padding can be washed or replaced asnecessary.

Referring now to FIGS. 2, 3, 6 and 7, posterior support 20 includesmolded in female rivet portions 34b. Plastic rivets 34 are used to holdposterior support padding 52 in place, as well as providing means forattaching hook-and-loop fasteners 54. Rivets 34 are also used forattaching occiput support 22 to posterior support 20.

As previously discussed, there are difficulties which arise whenattempting to find a material with sufficient rigidity to hold the headof a patient in a fixed position, while conforming circumferentially tothe neck of a patient. The same is true with the material used in thepresent invention, even though that material was chosen specifically forits properties in this regard. Accordingly, to add circumferentialflexibility to the collar, several openings 56a-f and 58a-f have beenadded to posterior support 20 and occiput support 22. These openings areuseful in adjusting the circumferential flex of the material whether thecollar is injection molded or die cut.

As can be seen from FIG. 2, openings 56a, 56b, and 56c are arranged in agroup, each having one end along a group line 60a. Similarly, openings58a, 58b, and 58c are also arranged in a group with one end along agroup line 62a. Both group lines 60a and 62a are vertical when a patientwearing the collar is in a seated or standing position.

As can also be seen from FIG. 2, openings 56a, 56b, and 56c are arrangedsuch that a second end of each opening not on group line 60a ispositioned along a second group line 60b. Group line 60b extends at anangle, from the bottom of posterior support 20 near group line 60a, atan angle up and away from group line 60a, and away from a vertical axisof symmetry 64. Similarly, openings 58a, 58b, and 58c are arranged witha second end along a second group line 62b which also angles up and awayfrom axis of symmetry 64, but on the opposite side thereof from groupline 60b.

Occiput support 22 also includes openings. Openings 56d, 56e, and 56fare located on the right side of occiput support 22. Openings 58d, 58e,and 58f are located on the left side of occiput support 22. When rearsemi-rigid portion 14 is assembled, openings 56d and 58d fall alonggroup lines 60a and 62a respectively. Openings 56e and 56f are arrangedsuch that a first end of each opening falls along a third group line 60cwhich is vertically arranged. The second end of each opening falls on afurther group line 60d. Openings 58e and 58f are also arranged such thata first end of each opening falls on group line 62c, and a second endfalls on a group line 62d. Group lines 60d and 62d may optionally bealigned with group lines 60b and 62b.

Posterior support 20 and occiput support 22 are symmetrical aboutvertical axis of symmetry 64 which passes through the horizontal centersof both posterior support 20 and occiput support 22. Openings 56d and58d are arranged along lines 60a and 62a respectively, and are arrangedvertically, that is they are longer in the vertical than the horizontaldirection.

Each of openings 56a-c and 58a-c are arranged with a first end of eachopening nearest vertical axis of symmetry 64 resting along group lines60a and 62a respectively. Each opening extends from group line 60a or62a away from axis of symmetry 64. Each opening also has the second endof the opening resting on second group line 60b or 62b. Openings 56a-cand 58a-c are arranged neither vertically nor horizontally, but extendat an angle away from lines 60a and 62a respectively. Openings 56a-f and58a-f are all oblong and of varying sizes. Although such openings workwell in the collar of the present invention, these openings may also beround or all of one size and configuration and still achieve the samefunction by employing a sufficient number in an effective arrangement.

The openings therefore form V-shaped areas between group lines 60a and60b, and between group lines 62a and 62b. Since material has beenremoved from posterior support 20 and occiput support 22 in theseV-shaped areas, posterior support 20 and occiput support 22 willpreferentially bend in these areas when force is applied. This allowsthe rear portion of the collar to conform more closely to the head of auser.

Also adding to the flexibility of posterior support 20 are verticalopenings 66. As may be seen in FIGS. 2 and 7, vertical openings 66 areshaped like arrows, to show a user which side of the collar should bepositioned on top when applied to a patient. However, the openings servethe function of increasing the flexibility of posterior support 20 toallow it to conform to the neck of the patient. Vertical openings 66 areplaced near the ends of posterior support 20, which allows those ends toflex more than the center of posterior support 20.

Posterior support 20 also includes hook-and-loop fastener openings 68.Hook-and-loop fastener 54 is secured to posterior support 20 by rivets34 located between vertical openings 66 and hook-and-loop fasteneropenings 68. The hook-and-loop fasteners 54 extend through hook-and-loopfastener openings 68 as may be seen from FIG. 2. This allows some of theforce on hook-and-loop fasteners 54 to be transferred directly toposterior support 20, to relieve some of the force placed on rivets 34by fasteners 54. Hook-and-loop fasteners 54 hold the collar in place andcan therefore receive considerable force which must be transferred tocollar 10.

Since the collar of the present invention is formed in two pieces, afront semi-rigid portion 12 and a rear semi-rigid portion 14, securingthe collar to a patient can be difficult. Accordingly, collar 10 hasbeen provided with a retaining strap 74. Retaining strap is an elasticstrap which attaches to sternum brace 16 at rivets 76 and 78. When thecollar is to be applied to a patient, the retaining strap 74 is placedloosely around the neck of the patient and fastened by hook and loopfasteners in area 26. Retaining strap 74 holds front semi-rigid portion12 loosely in place until rear semi-rigid portion 14 can be attached.Once rear semi-rigid portion 14 is attached, retaining strap 74 remainsin place, but performs no further function.

It is understood that various other modifications will be apparent toone skilled in the art without departing from the spirit and scope ofthis invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be construed as encompassing all thefeatures of patentable novelty that reside in the invention, includingall features that would be treated as equivalents thereof by thoseskilled in the art to which this invention pertains.

What is claimed:
 1. A joint in an orthopedic support unit comprising:afirst orthopedic support component; a female rivet portion molded intosaid first orthopedic support component and having:(a) a circular outerring, (b) a circular central receptacle, and (c) a plurality of straightreinforcing ridges extending between said circular outer ring and saidcircular central receptacle; a second orthopedic support component; anda male rivet portion having an end oversized relative to said circularcentral receptacle of said female rivet portion and extending throughsaid second orthopedic support component into said circular centralreceptacle of said female rivet portion for a press fit engagement withsaid female rivet portion.
 2. A joint in an orthopedic support unitaccording to claim 1 wherein said reinforcing ridges are equally spacedaround the circumference of said central receptacle.
 3. A joint in anorthopedic support unit according to claim 1 wherein said orthopedicsupport unit is a cervical collar, said first orthopedic supportcomponent is a sternum brace, and said second orthopedic supportcomponent is a jaw support.